Mr Grayling has two children, aged 20 and 16, with his wife Susan and told the Mail on Sunday he occasionally smacked them when they were younger.

"You chastise children when they are bad, as my parents did me," he said. "I'm not opposed to smacking. It is to be used occasionally. Sometimes it sends a message - but I don't hanker for the days when children were severely beaten at school."

Sources close to the minister said tonight he used the punishment on an "occasional" basis and only when "really warranted".